Once hired, regardless of your background, the airline will train you based on its procedures and its FAA-approved training curriculum. Even though all airlines fly the same kinds of airplanes, each airline has slightly different methods and procedures. The goal of an airline is to train you to be qualified in your position and to be standard. Standardization is one of the pillars of a safe airline. The concept is that, within the airline, cockpit behavior and procedure will be the same in every flight, no matter which pilots are at the controls, to prevent confusion and misunderstanding.
The initial training at an airline takes about 10 weeks. Basic indoctrination lasts a week or so. Training on general subjects, which include regulations and company-specific procedures, takes another week. You will spend two weeks on aircraft systems specific to the equipment you'll operate. Pilots will usually specialize in one type of airplane, such as 727s or MD-80s, until they move to a seat on a different airplane. After systems, you'll pair off with a training partner and have two or more weeks of simulator training. In the simulator, you'll experience just about every emergency and anomaly imaginable. You'll focus particularly on crew coordination and successful landing. All maneuvers are practiced until they are satisfactorily completed.
Once the pre-checks, oral examinations and final check-rides are over, you will have completed the airplane training. But you're not ready just yet. Next you'll fly with a special instructor pilot and get initial operating experience. This experience, which includes at least 25 hours of flight time, will teach you to integrate your newfound technical skills with the daily requirements of the job.
After initial operating experience, you face another flight test, called a line check. After you pass the line check, you are released to operate scheduled flights as a crew member. Airlines are now required to set up 100 hours of flying for you after a line check, so you can get immediate experience. After all that, you'll want a vacation.